COURSE/DISTRIBUTION: This is the largest artery
in the body. It begins its journey from the
aortic sinuses which separates it from the
aortic vestibule- the smooth outflow channel of
the left ventricle. It then ascends for a short
distance – a portion known as ascending aorta,-
to the right and behind the pulmonary trunk. It
forms an arch at the level of the sternal angle
of Louis which is placed at the imaginary plane
running from the manubrosternal junction to the
junction between vertebrae T4 and 5. The arch
runs posterior and slightly to the left and
ends at the same plane of sternal angle at the
back. This is the beginning of the descending
aorta. This runs a downward course close to the
vertebral bodies, initially to the left of the
bodies but slightly inclining towards the median
plane at the aortic opening in the diaphragm. On
the left it is accompanied by the oesophagus
which is to the right, and the inferior vena
cava, which joins it at the level of T7. The
descending aorta ends at the aortic opening at
the level of T12 in front of the diaphragmatic
median arcuate ligament, where the thoracic
arota escapes into the abdomen and becomes the
abdominal aorta.

The
abdominal aorta continues its downward
accompanied by the inferior vena cava which lies
to its right to the anterior aspect of L4 where
it divides into its two terminal branches –
common iliac arteries.